1. Field of the Invention
This invention relates in general to archery bows and more particularly, but not by way of limitation, to new and improved apparatus for changing bow strings, tension cable, wheels, etc., on an archer's compound bow and adjusting or tuning the bow and bow string.
2. Description of the Prior Art
With the development of compound or split limb bows and the widespread use thereof, there has arisen the attendant problem of replacing defective or worn bow strings, tension cables, wheels, etc., and providing and maintaining the proper tension on the bow string.
As is well known to those skilled in the art, the most popular form of compound bow includes two or more eccentrically mounted pulleys or wheels pivotally attached relative the bow limbs and serving to support and control the movement of a bow string which in turn is connected to a tension cable. The popularity of the compound bow is mainly due to the advantage provided in the reduced pull force required at full draw together with the resulting increase in accuracy. The pull on the bow string is high at the beginning of the draw but the arm at this point is able to exert maximum force. As the draw progresses a little beyond mid-point, there is an overcenter action on the eccentrically mounted pulleys or wheels which decreases the draw force needed to maintain the bow string in the drawn position without decreasing the energy stored in the limbs of the bow. Thus, at full draw it is relatively easy to hold the arrow and bow string and much easier to perfect aiming technique and proper finger release resulting in increased accuracy.
As will be appreciated by those familiar with compound bows, the stringing or outfitting of such a bow with its tension cable and bow string is very critical in order to achieve a proper balance or synchronization of the eccentrically mounted pulleys or wheels. The stringing or rigging makes it virtually impossible to unstring the bow when it is not in use. Thus, the limbs of compound bows are always under significant stress, which eventually leads to a degradation of the limb materials and a reduction in the bow weight (the amount of force needed to flex the bow limbs to a condition of full draw of the bowstring) with time for a given setting of the bow. This means that a periodic retuning of compound bows is needed to maintain desired performance levels. Also, over a period of time and with use, various elements of a compound bow, such as the bow string, the tension cable, a wheel or wheels, etc., need to be replaced and/or repaired.
In the past, when repairs or adjustments were required on the compound bow, it was necessary to take the bow to a shop which had a commercial bow press in order to make the adjustments or repairs. When a breakdown occurred or an adjustment was needed while on a hunting trip, the trip could be ruined unless additional spare bows were carried on the trip since a shop with a commercial bow press was not available out in the wilderness. The carrying of spare bows on the trip was a rather large burden.
In the prior art there are some devices which allow the bow string to be changed on a compound-type bow. For example, U.S. Pat. No. 4,074,409 discloses a bow string apparatus with attachment brackets for attaching a pull cord to the bow cables between the opposite eccentric pulley wheels and the bow string attachment points. The pull cord utilizes a low friction sheath member and a sliding locking bar for pulling tension on the bow and locking the bow in a compressed position while changing the bow string.
U.S. Pat. No. 4,599,987 discloses a bow press for restringing a split limb bow and includes a pair of spaced apart handles which engage the exterior of the limbs via slots formed therein. A rotatable lever to which the handles are interconnected, when rotated from a first position to a second position, causes inward compression of the limbs toward each other. An adjustment rod, which is variable in length, reduces or extends the length between the two handles to accommodate bows of various sizes.
The present invention is intended to provide a solution to the requirement that spare bows be carried on each hunting trip. The present invention also overcomes the inconvenience of needing to take the bow to a commercial shop for each adjustment and repair which is not only inconvenient but rather expensive.